"P*S" stands for Preventive Maintenance Monthly, the magazine for which Eisner provided (from 1951 up to the 1970's) illustrations and technical instructions (in comic-book form) on how to take care of military equipment and weapons. Eisner came up with the idea for this magazine, believing in the potential of the comics medium to communicate ideas and educate. This is from a somewhat controversial and perhaps underdocumented (in comparison to the time in which he was doing The Spirit, or his post-A Contract with God work) period in Eisner's career, so this book, written by someone who knew Eisner during that period, should make for interesting reading.

Fitzgerald has previously written a couple of appreciations of Eisner for the Washington Post (see here and here), the latter of which relates some Eisner anecdotes from the P*S period.

Further reading: Mike Ploog describes his time as an assistant to Eisner on P*S.